From: Matthew Wilcox <willy@infradead.org>
To: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Phillip Lougher <phillip@squashfs.org.uk>,
Xiongwei Song <Xiongwei.Song@windriver.com>,
Zheng Liang <zhengliang6@huawei.com>,
Zhang Yi <yi.zhang@huawei.com>, Hou Tao <houtao1@huawei.com>,
Miao Xie <miaoxie@huawei.com>,
Andrew Morton <akpm@linux-foundation.org>,
"linux-mm @ kvack . org" <linux-mm@kvack.org>,
"squashfs-devel @ lists . sourceforge . net"
<squashfs-devel@lists.sourceforge.net>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] squashfs: implement readahead
Date: Mon, 16 May 2022 13:36:10 +0100 [thread overview]
Message-ID: <YoJFOpbMYSEOGfXy@casper.infradead.org> (raw)
In-Reply-To: <CAJMQK-jjNRuZFOJrd2knQHwPERaJ64pyys+14cCVyfdsP1GZSQ@mail.gmail.com>
On Mon, May 16, 2022 at 07:04:08PM +0800, Hsin-Yi Wang wrote:
> > + loff_t req_end = readahead_pos(ractl) + readahead_length(ractl);
> > + loff_t start = readahead_pos(ractl) &~ mask;
> > + size_t len = readahead_length(ractl) + readahead_pos(ractl) - start;
> > + struct squashfs_page_actor *actor;
> > + unsigned int nr_pages = 0;
> > + struct page **pages;
> > + u64 block = 0;
> > + int bsize, res, i, index;
> > + int file_end = i_size_read(inode) >> msblk->block_log;
> > + unsigned int max_pages = 1UL << shift;
> > +
> > + readahead_expand(ractl, start, (len | mask) + 1);
> > +
> > + if (readahead_pos(ractl) + readahead_length(ractl) < req_end ||
> > + file_end == 0)
> > + return;
What's the first half of this condition supposed to be checking for?
It seems to be checking whether readahead_expand() shrunk the range
covered by the ractl, but readahead_expand() never does that, so I'm
confused why you're checking for it.
next prev parent reply other threads:[~2022-05-16 12:36 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-16 10:50 [PATCH 0/2] Implement readahead for squashfs Hsin-Yi Wang
2022-05-16 10:51 ` [PATCH 1/2] Revert "squashfs: provide backing_dev_info in order to disable read-ahead" Hsin-Yi Wang
2022-05-16 10:51 ` [PATCH 2/2] squashfs: implement readahead Hsin-Yi Wang
2022-05-16 11:04 ` Hsin-Yi Wang
2022-05-16 12:36 ` Matthew Wilcox [this message]
2022-05-16 12:47 ` Hsin-Yi Wang
2022-05-16 12:55 ` Matthew Wilcox
2022-05-16 12:57 ` Hsin-Yi Wang
2022-05-16 14:21 ` kernel test robot
2022-05-17 3:40 ` Phillip Lougher
2022-05-16 16:01 ` kernel test robot
2022-05-17 3:41 ` Phillip Lougher
2022-05-17 3:35 ` [PATCH 3/2] squashfs: always build "file direct" version of page actor Phillip Lougher
2022-05-17 7:51 ` Hsin-Yi Wang
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